I'm trying to implement a serial adder/subtractor in VHDL, I've done it the ripple carry way before but now I'm supposed to implement the same functionality by just using one full adder cell instead of N-amount of cells so I have to shift the bits from the vectors in to the full adder/subtractor and store the result in another vector which I just shift the index for as well. The logic behind it is very easily understood, you just have a counter for the index and so on. But I obviously encounter problems since I'm probably still thinking a bit too much software programming I guess. Cdilla dll autocad 2002 tutorial free. The problem I have is that the counter increases to 1 right away when it enters the process so that when I try to add the vectors a = 0101 0101 and b = 1010 1010 I get y = 1111 111X and the carrys = 0000 000X. Osmonitor full crack idm full.
I've tried to start storing the result at index_counter - 1 since the index jumps to 1 on the first clock cycle, but then I get a fatal error in the simulation. I've been trying to solve this problem for a few hours now and can't seem to figure out how to do it, so could you please take a look and see what I can do to fix it? Would be very much appreciated! I do have signals for saturation and overflow that I am going to implement later on but they aren't really used at the moment so don't worry about them. The design shouldn't update the final result before the addition/subtraction is finished if you're wondering why I have done it the way I have. I haven't tried to debug this, but I think it is a timing problem: At the very first rising clock edge, you define both the inputs to your adder and register the adder's outputs (which are X at this point, because its inputs weren't defined before).
With the idea of storing the result at index_counter - 1 you are on the right track however you need to take care that you never try to store the result in a non-existing register such as carry(-1) or temp_sum(-1). You can use if index_counter > 0 for that for example. Similarly, you then need to allow for one more cycle at the end of the calculation or assign the last result bit directly to your y output or you'll miss the last result bit.
Hope that helps!
Jul 17, 2013 - Design of Serial IN - Parallel OUT Shift Register using Behavior Modeling. Design of 4 Bit Adder cum Subtractor using Structural Modeling Style (Verilog CODE). Output Waveform: 4 Bit Adder / Subtractor. Verilog CODE.
I'm trying to implement a serial adder/subtractor in VHDL, I've done it the ripple carry way before but now I'm supposed to implement the same functionality by just using one full adder cell instead of N-amount of cells so I have to shift the bits from the vectors in to the full adder/subtractor and store the result in another vector which I just shift the index for as well. The logic behind it is very easily understood, you just have a counter for the index and so on. But I obviously encounter problems since I'm probably still thinking a bit too much software programming I guess. Cdilla dll autocad 2002 tutorial free. The problem I have is that the counter increases to 1 right away when it enters the process so that when I try to add the vectors a = 0101 0101 and b = 1010 1010 I get y = 1111 111X and the carrys = 0000 000X. Osmonitor full crack idm full.
I've tried to start storing the result at index_counter - 1 since the index jumps to 1 on the first clock cycle, but then I get a fatal error in the simulation. I've been trying to solve this problem for a few hours now and can't seem to figure out how to do it, so could you please take a look and see what I can do to fix it? Would be very much appreciated! I do have signals for saturation and overflow that I am going to implement later on but they aren't really used at the moment so don't worry about them. The design shouldn't update the final result before the addition/subtraction is finished if you're wondering why I have done it the way I have. I haven't tried to debug this, but I think it is a timing problem: At the very first rising clock edge, you define both the inputs to your adder and register the adder's outputs (which are X at this point, because its inputs weren't defined before).
With the idea of storing the result at index_counter - 1 you are on the right track however you need to take care that you never try to store the result in a non-existing register such as carry(-1) or temp_sum(-1). You can use if index_counter > 0 for that for example. Similarly, you then need to allow for one more cycle at the end of the calculation or assign the last result bit directly to your y output or you'll miss the last result bit.
Hope that helps!
Jul 17, 2013 - Design of Serial IN - Parallel OUT Shift Register using Behavior Modeling. Design of 4 Bit Adder cum Subtractor using Structural Modeling Style (Verilog CODE). Output Waveform: 4 Bit Adder / Subtractor. Verilog CODE.
...">Verilog Code For Serial Adder And Subtractor(29.12.2018)I'm trying to implement a serial adder/subtractor in VHDL, I've done it the ripple carry way before but now I'm supposed to implement the same functionality by just using one full adder cell instead of N-amount of cells so I have to shift the bits from the vectors in to the full adder/subtractor and store the result in another vector which I just shift the index for as well. The logic behind it is very easily understood, you just have a counter for the index and so on. But I obviously encounter problems since I'm probably still thinking a bit too much software programming I guess. Cdilla dll autocad 2002 tutorial free. The problem I have is that the counter increases to 1 right away when it enters the process so that when I try to add the vectors a = 0101 0101 and b = 1010 1010 I get y = 1111 111X and the carrys = 0000 000X. Osmonitor full crack idm full.
I've tried to start storing the result at index_counter - 1 since the index jumps to 1 on the first clock cycle, but then I get a fatal error in the simulation. I've been trying to solve this problem for a few hours now and can't seem to figure out how to do it, so could you please take a look and see what I can do to fix it? Would be very much appreciated! I do have signals for saturation and overflow that I am going to implement later on but they aren't really used at the moment so don't worry about them. The design shouldn't update the final result before the addition/subtraction is finished if you're wondering why I have done it the way I have. I haven't tried to debug this, but I think it is a timing problem: At the very first rising clock edge, you define both the inputs to your adder and register the adder's outputs (which are X at this point, because its inputs weren't defined before).
With the idea of storing the result at index_counter - 1 you are on the right track however you need to take care that you never try to store the result in a non-existing register such as carry(-1) or temp_sum(-1). You can use if index_counter > 0 for that for example. Similarly, you then need to allow for one more cycle at the end of the calculation or assign the last result bit directly to your y output or you'll miss the last result bit.
Hope that helps!
Jul 17, 2013 - Design of Serial IN - Parallel OUT Shift Register using Behavior Modeling. Design of 4 Bit Adder cum Subtractor using Structural Modeling Style (Verilog CODE). Output Waveform: 4 Bit Adder / Subtractor. Verilog CODE.
...">Verilog Code For Serial Adder And Subtractor(29.12.2018)